1. Field of the Invention
Example embodiments of the invention relate to a solar cell and a method of manufacturing the same.
2. Description of the Related Art
Recently, as existing energy sources such as petroleum and coal are expected to be depleted, interests in renewable energy sources for replacing the existing energy sources are increasing. As a source of the renewable energy, solar cells for generating electric energy from solar energy have been particularly spotlighted.
A solar cell generally includes a substrate and an emitter layer, each of which is formed of a semiconductor, and electrodes respectively formed on the substrate and the emitter layer. The semiconductors forming the substrate and the emitter layer have different conductive types, such as a p-type and an n-type. A p-n junction is formed at an interface between the substrate and the emitter layer.
When light is incident on the solar cell having the above-described structure, electrons inside the semiconductors become free electrons (hereinafter referred to as “electrons”) by the photoelectric effect. Further, electrons and holes respectively move to the n-type semiconductor (e.g., the emitter layer) and the p-type semiconductor (e.g., the substrate) based on the principle of the p-n junction. The electrons moving to the emitter layer and the holes moving to the substrate are respectively collected by an electrode connected to the emitter layer and an electrode connected to the substrate.
A solar cell capable of increasing the size of a light receiving area by forming both an electron electrode and a hole electrode on a back surface of the substrate (i.e., the surface of the substrate on which light is not incident) has been recently developed. Hence, the efficiency of the solar cell is improved.